Login or Register to Ask a Question and Join Our Community


Shell Programming and Scripting

Passing Variable to Regular Expression

Login to Discuss or Reply to this Discussion in Our Community

 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting Passing Variable to Regular Expression
# 8  
Old 12-16-2010
Code:
read name
grep "^$name" AIDNameList.txt

Even this will satisfy your requirement. Please correct if I missed judged your point.
R0H0N
# 9  
Old 12-16-2010
It worked now. Smilie

---------- Post updated at 04:57 PM ---------- Previous update was at 04:53 PM ----------

Quote:
Originally Posted by pludi
Sorry, my bad, you'll have to chomp the input, otherwise it'll include the newline character in the search:
Code:
print "Enter the Name:  ";
my $Name = <>;
chomp $Name;
print "Word is $Name";

open my $FH, '<', 'AIDNameList.txt' or die "Can't read AIDNameList: $!";
print grep { /$Name/ } <$FH>;
close $FH;

Besides, what's wrong with using a regular grep?
Thank u So much .. I simply didnot somehow consider using grep.
# 10  
Old 12-16-2010
Quote:
Originally Posted by pludi
Sorry, my bad, you'll have to chomp the input, otherwise it'll include the newline character in the search:
Code:
print "Enter the Name:  ";
chomp ( my $Name = <> ) ;
#chomp $Name;
print "Word is $Name";

open my $FH, '<', 'AIDNameList.txt' or die "Can't read AIDNameList: $!";
print grep { /$Name/ } <$FH>;
close $FH;

Besides, what's wrong with using a regular grep?
sorry jisha for stealing your thread, i did 1 line change making chomp when in accept the input. i use this frequently but i have not seen in actual coding. can someone tell me reason ? if there is any reason behind it.
# 11  
Old 12-17-2010
I used to get unexpected output before chomp was used. chomp removes the trailing strings usually the new line character. it should be used because a string with a newline character and same string with out the new line charecter are different.
eg: $Name = "Alina"; and $Name = "Alina " are different .

Regular expression search will not return the intended value if chomp is not used in these cases .
# 12  
Old 12-21-2010
Quote:
Originally Posted by jisha
I used to get unexpected output before chomp was used. chomp removes the trailing strings usually the new line character. it should be used because a string with a newline character and same string with out the new line charecter are different.
eg: $Name = "Alina"; and $Name = "Alina " are different .

Regular expression search will not return the intended value if chomp is not used in these cases .
i know why chomp is used, but i want to know, why its used like below
Code:
my $input = <STDIN> ; 
chomp $input ;

and not like below
Code:
chomp ( my $input = <STDIN> ) ;

# 13  
Old 12-21-2010
Habit, mostly. I like my variables declared before I pass them to any functions. But as always TMTOWTDI.
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

How to store regular expression in a variable?

Hi, Im facing a weird behavior storing regular expression in a vaiable. Let us consider >file_name=CTP02_*.tar when I echo the above variable its displaying below which is file CTP02_*tar but when I create a file with name CTP02_1234.tar, and when I echo $file_name its showing... (3 Replies)
Discussion started by: rdineshredy
3 Replies

2. Shell Programming and Scripting

Regular expression as a variable

I'm trying to use a series of regular expressions as variables but can't get it to behave properly. You can see below what I'm trying to do. Here with lowercase a-z and the same with uppercase, numbers 0-9 and again with a set of special characters, without having to type out every single... (3 Replies)
Discussion started by: 3therk1ll
3 Replies

3. Shell Programming and Scripting

Passing regular expression to nawk

I am trying to test if I can replace a regular expression in 'nawk' with a variable. Please let me know why it is not working. I am using ksh88i on solaris8 I am trying use this test as a building block to filter active external DNS connections. Ideally I want to pass variable defined... (4 Replies)
Discussion started by: kchinnam
4 Replies

4. UNIX for Dummies Questions & Answers

grep with variable and regular expression

i have a command line like this in csh script grep -i "$argv$" which i wanted to select the line ending with string provided as argument but it couldn't interpret the '$' (ending with).. any help? (3 Replies)
Discussion started by: ymc1g11
3 Replies

5. Shell Programming and Scripting

passing a regex as variable to awk and using that as regular expression for search

Hi All, I have a sftp session log where I am transferring multi files by issuing "mput abc*.dat". The contents of the logfile is below - ################################################# Connecting to 10.75.112.194... Changing to: /home/dasd9x/testing1 sftp> mput abc*.dat Uploading... (7 Replies)
Discussion started by: k_bijitesh
7 Replies

6. Programming

Perl: How to read from a file, do regular expression and then replace the found regular expression

Hi all, How am I read a file, find the match regular expression and overwrite to the same files. open DESTINATION_FILE, "<tmptravl.dat" or die "tmptravl.dat"; open NEW_DESTINATION_FILE, ">new_tmptravl.dat" or die "new_tmptravl.dat"; while (<DESTINATION_FILE>) { # print... (1 Reply)
Discussion started by: jessy83
1 Replies

7. Shell Programming and Scripting

Passing in regular expression as a parameter to sed

Hi All, Im using Bash. I have a pipe delimited config file which contains 3 columns, 1st column = location of a file to be chnaged 2 column = expression to find within file 3rd column = string to replace. A script will loop through the contetnts of this file and apply the changes using... (2 Replies)
Discussion started by: satnamx
2 Replies

8. Shell Programming and Scripting

Awk's variable in regular expression

Anyone know how I will use awk's variable in a regular expression? This line of code of mine is working, the value PREMS should be a variable: awk '$1 ~ /PREMS/ { if(length(appldata)+2 >= length($1)) print $0; }' appldata=$APPLDATA /tmp/file.tmp The value of APPLDATA variable is PREMS. ... (2 Replies)
Discussion started by: Orbix
2 Replies

9. Shell Programming and Scripting

compare variable against regular expression?

is it possible? if so, how? i want to check a variable whether is it a number or letter in an if-else statement (6 Replies)
Discussion started by: finalight
6 Replies

10. Shell Programming and Scripting

regular expression using a variable

hello, I use AIX with ISM PILOT, I want to match something with a varible like this : $variable = 10 #this variable is the number of the job "$variable STARTED" # the pattern how can use this variable to match it with the word STARTED Tanks (0 Replies)
Discussion started by: barribar
0 Replies
Login or Register to Ask a Question